# Distribution graph

This graph page provides several ways to visualize the distribution of performance measurements across time intervals.

MyKeynote offers several different distribution graph styles, which you can select in the **Distribution Graph Type** list on the chart configuration page. This page also provides a control for the *interval*, that is, the number of buckets or time slices that will be shown in the graph.

### Actions for this graph

The Actions menu at the top right of the Distribution graph provides access to several tools to help make use of the graph and its underlying data.

See Chart Actions for information about graph page controls that you can use to save graphs, download data, and refresh the graph.

## Distribution graph types

These graph types are available:

### Histogram graph

This is the default graph style for distribution graphs. Each vertical bar represents one time bucket, with the height of the bar indicating the count of data points that fell within that time bucket. Each time bucket represents a second.

*Distribution Graph - Histogram*

### Frequency polygon graph

Similar to a histogram, this graph type contains one point representing the number of data points for each time bucket.

### Ogive graph

This is a cumulative frequency graph. Each dot on the graph represents the number of measurements that were at or below the corresponding time segment.

### Box plot

This graph type provides a quick way to visualize the number of measurements that lie within the lowest, second, third, and fourth quartiles of measured data points. It also shows the lowest and highest data points.

The box plot is a graphical display of a five number summary, including: the smallest observation, lower quartile (Q1), median, upper quartile (Q3), and largest observation.

This process is followed to draw a box plot:

- Draw a box from the 25th to the 75th percentile.
- Split the box with a line at the median.
- Draw a thin lines (whisker) from the 75th percentile up to the maximum value.
- Draw another thin line from the 25th percentile down to the minimum value.

The length of the box in a box plot, that is, the distance between the 25th and 75th percentiles, is known as the interquartile range. You can use this box length to detect outliers. If any whisker is more than 1.5 times as long as the length of the box, then we have evidence of outliers. A common variation on the box plot is to draw the whisker to the value which is just shy of 1.5 box lengths away, and highlight each individual data point more than 1.5 box lengths away.

## Study legend

When setting up a distribution graph on the Graph Settings page you have the option to add a legend to the graph. When Study is set to Yes, a legend appears next to the graph with distribution details, and the distribution graph is overlaid with color bands indicating the lower, upper and middle quartiles.

*Distribution - Histogram graph with study legend*

*Distribution - Frequency Polygon graph with study legend*

*Distribution - Ogive graph with study legend*

*Distribution - Box Plot graph with study legend*